This proposal is to study the role of angiotensin II and its physiological effects on blood pressure, plasma aldosterone release and inhibition of renin release in normal subjects and compare with subjects with hypertension, cirrhosis and ascites and patients with Bartter's syndrome. Using a newly developed radioimmunoassay for angiotensin II, sensitivity of the blood pressure or plasma aldosterone will be better defined in these patients. In addition, the response of these parameters to infusion of saralasin (1-sar-8-ala-angiotensin II), in the oral converting enzyme inhibitor (SQ 14-225) will be analyzed. It is anticipated that a better understanding of the role of angiotensin II sensitivity on the vascular, adrenal and kidney in hypertensive patients should facilitate the management of hypertension in the future.